A polycarbonate resin is prepared by condensation-polymerization of an aromatic diol such as bisphenol A with a carbonate precursor such as phosgene and has excellent mechanical and heat properties. Particularly, the polycarbonate resin has high impact resistance at room temperature, and has excellent dimensional stability. Until now, studies on a technology of implementing excellent physical property by adding various kinds of fillers into the polycarbonate resin have been conducted.
Recently, study on a polycarbonate resin composition having increased processability by mixing an acrylonitrile-butadiene-styrene (ABS)-based copolymer has been actively conducted in addition to the polycarbonate resin, wherein the polycarbonate resin is generally referred to as a PC/ABS resin or a PC/ABS alloy. In case of the PC/ABS resin, in order to improve a mechanical property, an inorganic filler (for example, talc) is added to the PC/ABS resin, so that the mechanical property may be improved. However, there is a drawback such as flow mark at the time of injection molding. When an appearance defect such as flow mark occurs, additional processes such as a coating process, etc., are required as post treatment processes, so that production cost is increased.
Meanwhile, in order that the polycarbonate resin is applied to more various fields, many studies have been conducted to obtain a desired physical property by copolymerizing two or more aromatic dial compounds having different structures and introducing units having different structures in a main chain of the polycarbonate.
Given the above circumstances, the present inventors have been made in an effort to solve a problem of appearance defect caused by including the inorganic filler in the polycarbonate resin, and as a result, found that at the time of including a copolycarbonate comprising two or more different repeating units together in addition to the inorganic filler as described below, the problem of appearance defect is capable of being solved while maintaining an effect of improving a mechanical property according to the addition of the inorganic filler, and completed the present invention.